random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 IP: [] l2tp_session_free+0x11c/0x200 net/l2tp/l2tp_core.c:1765 PGD 1c2247067 [ 33.452044] PUD 1c141e067 Oops: 0002 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 3759 Comm: syz-executor632 Not tainted 4.9.124-g09eb2ba #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801bd8ee000 task.stack: ffff8801bc1c8000 RIP: 0010:[] [] l2tp_session_free+0x11c/0x200 net/l2tp/l2tp_core.c:1765 RSP: 0018:ffff8801bc1cfc98 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff8801ca6f9900 RCX: 0000000000000000 RDX: 1ffff10037848970 RSI: ffffffff836c4711 RDI: ffff8801bc244b80 RBP: ffff8801bc1cfcb8 R08: ffff8801bd8ee8e8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801bc244a00 R13: ffff8801ca6f9908 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000001f13880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000080 CR3: 00000001c1573000 CR4: 00000000001606f0 Stack: ffff8801d57ac400 ffff8801ca6f9900 ffff8801d57ac7d0 ffff8801d57ac6d8 ffff8801bc1cfce0 ffffffff836cc022 ffff8801d57ac840 ffff8801d57ac400 ffffffff836cbf50 ffff8801bc1cfd18 ffffffff830281f5 ffff8801d57ac840 Call Trace: [] l2tp_session_dec_refcount_1 net/l2tp/l2tp_core.h:297 [inline] [] pppol2tp_session_destruct+0xd2/0x110 net/l2tp/l2tp_ppp.c:460 [] __sk_destruct+0x55/0x590 net/core/sock.c:1428 [] sk_destruct+0x63/0x80 net/core/sock.c:1463 [] __sk_free+0x4f/0x220 net/core/sock.c:1471 [] sk_free+0x2b/0x40 net/core/sock.c:1482 [] sock_put include/net/sock.h:1588 [inline] [] pppol2tp_release+0x239/0x2e0 net/l2tp/l2tp_ppp.c:501 [] __sock_release+0xd7/0x260 net/socket.c:605 [] sock_close+0x19/0x20 net/socket.c:1059 [] __fput+0x263/0x700 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x10c/0x180 kernel/task_work.c:116 [] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161 [] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline] [] syscall_return_slowpath arch/x86/entry/common.c:260 [inline] [] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: 49 8d bc 24 80 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c6 00 00 00 4d 8b b4 24 80 01 00 00 41 ff 8e 80 00 00 00 74 69 e8 a5 c5 c9 fd 4c 89 ea 48 b8 00 RIP [] l2tp_session_free+0x11c/0x200 net/l2tp/l2tp_core.c:1765 RSP CR2: 0000000000000080 ---[ end trace 337db620c01e4434 ]---